Embodiments of the present invention relate to a 3D image analyzer for determining the gaze direction (i.e. direction vector) or a line of sight (consisting of position vector and direction vector) within a 3D room without the necessity of a calibration by the user, the gaze direction of whom is to be determined. Further embodiments relate to an image analyzing system with a 3D image analyzer for recognizing an alignment and/or gaze direction and to a corresponding method for recognizing the alignment and/or gaze direction.
For the automatic determination of the human gaze direction, there are different categories of systems. One common category are the video-based systems, which record with one or more cameras the eyes of the person and analyze these video recordings online or offline in order to determine therefrom the gaze direction.
Systems for a video-based determination of the gaze direction as a rule necessitate for each user prior to the use and in some cases additionally during the use (e.g. when leaving the camera's detection zone or in the event of a change of the position between user and system) a calibration procedure in order to be able to determine the gaze direction of the user. Furthermore, some of these systems necessitate a very specific and defined arrangement of the camera(s) and the illumination to each other or a very specific arrangement of the camera(s) towards the user and a previous knowledge about the user's position (as e.g. disclosed in the German patent no. DE 10 2004 046 617 A1) in order to be able to perform the determination of the gaze direction.
Therefore, there is the need for an improved concept.